Vince,
Here's a little bit of history about the LS3/5a from an Enjoy the Music review of the Gini LS3/5a. One thing they do mention is that the LS3/5a is a "monitor speaker" and not a "bookshelf speaker".
"Surely it must come to pass that in every audiophile life there is a moment of regret, something you would undo if you could. For me that moment was the day I sold my Chartwell LS3/5A Speakers. Now as I look back, it is 31 years since the speakers were first produced in 1975. The first American report I could find was back in March 1977 when J. Gordon Holt reviewed a BBC pair that at the time retailed for $430. The initial production run was small and only meant to fit a very specific need at the time. But that ended when audiophiles discovered the wonderful musical qualities inherent in this LS3/5a specification. Very few speakers have retained such a loyal following over so many years. If you do a web search as I did you might find an LS3/5a chat room. Looking through this site I found a British member reporting that in April of 2005 a pair of Chartwell LS3/5a speakers went for the U.S. equivalent of $2,500 on an e-Bay auction. The speakers have garnered a cult status very much like the acclaimed Marantz 9 amplifiers and Quad 57 electrostatic speakers. Production eventually came to a halt in 1998 when KEF ceased production of the T27 tweeter and the B110 midrange/woofer that was at the very heart of the design. This speaker is designated a Class 2 near field monitor and was developed after extensive research by the British Broadcasting Company (BBC) in the mid seventies.
The BBC had a need for a small monitor speaker that they could use in confined spaces like vans and control rooms. However this speaker is definitely not a bookshelf design. It should be placed well away from walls and placed on stands between 24" and 30" high when used in a domestic environment. It might not be widely known but there were actually two different versions that conformed to the BBC speaker specification. The initial production run manufactured a speaker with a 15 Ohm impedance and in later versions the speaker was a more compatible 11 Ohm load. The finalized 11 Ohm crossover was designated FL6/38 SP2128 and around 1987 both the crossover and drivers were supplied by KEF who started using computer aided matching. With KEF supplying both the drivers and the crossovers an ongoing problem with variability was largely resolved. Long time fans of this speaker will tell you that the later 11 Ohm version had a quicker more modern sound and that the 15 Ohm version had a more seductive vocal presentation.
A very important fact to keep in mind is that there never was any intention to design a totally neutral speaker with ruler flat response. The intention was and is to establish a standard and rigorously maintain control over all performance parameters. Having done that any LS3/5a speaker can be mixed or matched with any other LS3/5a speaker no matter when it was made and who may have manufactured it. Ultimately during the span of this 23-year production run they were produced under seven different licensed brand names they were in alphabetical order, the BBC, Chartwell, Goodmans, Harbeth, KEF, Rogers, and Spendor. I am discounting three other wannabe companies that failed or had little or no impact on production. With varying degrees of failure they were Audiomaster, RAM, and JPW. The Spendor speakers were I believe the second most prolific brand name associated with this product. The Spendor Company derived its name from the founders Spencer and Dorothy Huges. H.D. Harwood founded the Harbeth Company and another of the licensees was Richard Ross of Rogers. The combined output of these manufacturers ultimately totaled an astounding one hundred thousand pairs of LS3/5a speakers. One company in particular, the British company Rogers had a very long involvement with this project starting almost at the very beginning and I believe they account for the majority of the speakers now extant. The preceding narrative is only a very small portion of a very large book and even now the last chapter has not been written."
Btw, the Gini LS3/5a are modern and much more affordable speakers that attempts to "get" much of what was desired in the "classic" British manufactuered LS3/5a. But the fact still remains that IT IS NOT a "true" LS3/5a, although it does do a good job of capturing much of what is desired in a LS3/5a type of speaker.